Planta
Abstract. Sixty one members of the Poaceae, including various cereals, were grown in defined nutrient media with and without the arbuscular mycorrhizal (AM) fungus, Glomus intraradices Schenk Smith. The roots of all species investigated were colonized by the AM fungus, however, to different degrees and independent of their systematic position. High-performance liquid chromatographic analyses of methanolic...
Abstract. Total proteins extracted from developmental mutants of Arabidopsis thaliana (L.) Heyhn. and from wild-type plants cultivated in the presence of various hormones were analyzed by two-dimensional (2-D) gel electrophoresis. Computer analysis of 2-D gels followed by a statistical treatment of data allowed us to build a phenogram that describes the biochemical distances between the different...
Abstract. Despite the availability of many mutants for signal transduction, Arabidopsis thaliana guard cells have so far not been used in electrophysiological research. Problems with the isolation of epidermal strips and the small size of A. thaliana guard cells were often prohibiting. In the present study these difficulties were overcome and guard cells were impaled with double-barreled microelectrodes...
Abstract. A panel of monoclonal antibodies (MAC204, MAC236, MAC265) which recognise extracellular matrix glycoproteins implicated in plant-microbe interactions has been used to study glycoprotein antigens in petioles of turnip (Brassica campestris L.). While MAC204 recognised two glycoproteins (gp120 and gp45) with apparent Mr120000 and 45000 in petiole extracts made with 2-amino-2-(hydroxymethyl)-1,3-propanediol...
Abstract. Calcium-stimulated protein kinase activity in the flagella of the green alga Chlamydomonas moewusii (Gerloff) was characterised. Using SDS-PAGE and an on-blot phosphorylation assay, a 65-kDa protein was identified as the major calcium-stimulated protein kinase. Its activity was directly stimulated by calcium, a characteristic of the calmodulin-like domain protein kinases (CDPKs). Monoclonal...
Abstract. The activity and intercellular distribution of sucrose-phosphate synthase (SPS; EC 2.4.1.14) were determined in fully expanded leaves from a range of C4 plants. In Zea mays L. and Atriplex spongiosa F. Muell., SPS was located almost exclusively in the mesophyll cells. In other species, SPS was found in both cell types, with the activity in the bundle sheath cells ranging from 5% of the total...
Abstract. The microrelief of plant surfaces, mainly caused by epicuticular wax crystalloids, serves different purposes and often causes effective water repellency. Furthermore, the adhesion of contaminating particles is reduced. Based on experimental data carried out on microscopically smooth (Fagus sylvatica L., Gnetum gnemon L., Heliconia densiflora Verlot, Magnolia grandiflora L.) and rough water-repellent...
Abstract. This study addresses the still open question of whether or not in oily storage tissues, e.g. cotyledons of germinating rape (Brassica napus L.) seedlings lipase (triacylglycerol acylhydrolase, EC 3.1.1.3) and the -oxi-dation system of fatty acids are located in one or more membrane-bounded organelles. The organelles were isolated carefully and identified by marker-enzyme activities. Activities...
Abstract. The synthesis of -aminolevulinic acid (-ALA) is a key step in the regulation of tetrapyrrole synthesis. To study the developmentally and circadian-clock controlled mechanism that co-ordinates synthesis of chlorophylls and chlorophyll-binding proteins, -ALA-synthesising capacity was analysed in barley (Hordeum vulgare L.) primary leaves grown under dark/light or constant light conditions...
Abstract. Flavonol-deficient petunia pollen [conditionally male fertile (CMF) pollen] is unable to germinate but application of nanomolar concentrations of flavonol aglycones completely restores function (Mo et al. 1992). In this study a chemically synthesized radioactive flavonol, [4-O-14C]kaempferide, was used as a model compound to study the metabolism of flavonols during the first few hours of...
Abstract. Over 90% of the germ tubes of Puccinia graminis tritici (wheat stem rust) and Puccinia hordei (barley brown rust) differentiate appressoria on encountering stomata.There has been controversy as to the role of host topographical signals in the highly precise and efficient induction of these infection structures over stomata by cereal rusts. In the present study, polystyrene replicas of microfabricated...
Abstract. Enhanced deposition and cross-linking of hydroxyproline-rich glycoproteins (HRGPs) in the plant cell wall is acknowledged to contribute to the formation of a resistant barrier against pathogen infection. We have isolated, from suspension-cultured potato (Solanum tuberosum L. cv. Desiree) cells, two forms of soluble HRGP, a cross-linked and a monomeric form; the latter can be converted to...
Abstract. Previous studies have indicated that ent-kaurene synthase (KS) is located in the proplastid stroma of rapidly dividing plant tissues. Here we present further and more direct evidence for this hypothesis and follow the activity of KS throughout the entire vegetative growth period of wheat plants. During germination of wheat caryopses, KS activity was maximal for a short period culminating...
Abstract. We report the ATP-mediated activation of sucrose-phosphate synthase in bundle sheath cells prepared from C4 species. Sucrose synthesis was followed by measuring the incorporation of [14C]fructose 6-phosphate into sucrose in bundle sheath cells also provided with uridine 5-diphosphoglucose (UDPGlc). Studies with Panicum miliaceum L. cells showed that activation was largely due to an increase...
Abstract. A highly synchronised in-vitro tuberisation system, based on single-node cuttings containing an axillary bud, was used to investigate the activity patterns of enzymes involved in the conversion of sucrose to hexose-phosphates during stolon-to-tuber transition of potato (Solanum tuberosum L.). Two different non-tuberising systems were included to distinguish between changes that are or are...
Abstract.1-Pyrroline-5-carboxylate (P5C) dehydrogenase (EC 1.5.1.12) activity was measured in extracts from cultured tobacco (Nicotiana plumbaginifolia Viviani) cells. Two putative isozymes were resolved by anion-exchange fast protein liquid chromatography. These enzyme forms showed different patterns of expression during the culture growth cycle: activity-I increased in exponentially growing cells...
Abstract. In the 3-d-old 2-mm root tip of Pisum sativum L. cv. Lincoln the percentage of actively proliferating cells is estimated to be 70%. The remaining cells are non-cycling and arrested with 2C and 4C DNA content in G0 and in G2Q, respectively. In this work we studied the kinetic significance of these quiescent cells, using the sorting capabilities of flow cytometry and immunofluorescence techniques...
Abstract. Jasmonic acid, a product of the lipoxygenase (LOX) pathway, has been proposed to be a signal transducer of defence reactions in plants. We have reported previously that methyl jasmonate (MJ) induced accumulation of proteinase inhibitors in tobacco cell suspensions (Rickauer et al., 1992, Plant Physiol Biochem 30: 579584). The role of this compound in the induction of this and of other defence...
Abstract. Circumnutation is an oscillating movement of a growing plant organ that is believed to result from an endogenous rhythmic process intrinsic to growth. Circumnutating organs, as they extend, describe a helical trace. In Arabidopsis thaliana (L.) Heynh. circumnutation is particularly evident in primary roots and occurs, as in most plants, in a right-handed direction when viewed from above...